Hi all

the attached is a booster amp used a gain boosted ota, from one berkeley student's project report.

I don't understand why he used cascoded tail current source with one transistor controlled by biasing network and another by cmfb. Any particular advantage of this topology compared to normal cmfb tail current source (two parallel transistor)?

Thanks!

Perhaps he using this method to close the CMFB loop. Never seen anyone do it like this before. If you plan to use it, make sure you write the equations well and simulate it (esp startup conditions since you will could have a zero operating point, ie the output is zero and the ckt still converges).